1. Technical Field of the Invention
The present invention relates to three-dimensional imaging systems and, in particular, to the camera systems, image data manipulation systems and image display systems necessary for taking, generating, transmitting and reproducing true three-dimensional images.
2. Description of Related Art
The most commonly recognized example of three-dimensional image perception is that experienced with human vision. Although each eye views the same scene, the horizontal displacement between the eyes allows each eye to view that same scene and any objects located therein from a slightly different perspective. For example, one eye will see slightly more around a corner or curved surface of a viewed object than the other eye. Breaking up the viewed scene into a plurality of picture elements reveals that corresponding elements viewed by each of the eyes are slightly displaced horizontally from one another due to the depth of (or distance to) the object. The brain receives the displaced images from each eye, and compares and combines (i.e., converges) the images to perceive differences in distances between the various objects in the viewed scene. This visual effect is commonly referred to as stereoscopy.
Considerable effort and expense has been invested in the development of methods and systems for processing taken two-dimensional images so as to permit viewers to perceive the taken images in three dimensions. Such methods and systems commonly utilize eye-to-eye parallax to provide depth information by taking two-dimensional images from two slightly different perspectives. The images are individually viewed by different eyes to produce stereoscopic effects by means of blinker-like shields or binocular apparatus worn about the eyes.
As an alternative to separate eye display of the two slightly different perspective two-dimensional images, the images are instead overlaid on each other as an analglyph and displayed on a single screen. The images are separated from each other for human viewing and stereoscopic perception through the use of spectacles having a different coloring or polarizing filter for each eye. In yet another alternative, the two images are alternatively displayed on a single screen with the eyes of the observer alternatively occluded by spectacle mounted shutters actuated in phase with the alternating image display to produce a stereoscopic effect.
Each of the foregoing three-dimensional imaging solutions effectively produces three-dimensional images for viewing, but inconveniently requires the use of some sort of apparatus (like spectacles) to be worn about the eyes of the viewer. A further drawback experienced with such solutions is that the viewer is limited to the point of view from which the images are taken for experiencing the three-dimensional effect. True (i.e., multi-point of view) three-dimensional viewing where the sides of objects as well as objects hidden behind other objects are revealed by lateral viewer movement with respect to the taken images is not possible using any of the foregoing methods.
Three-dimensional images may be produced without use of viewer worn apparatus by means of a parallax barrier strip or sheet of parallel lenticular lenses. In such a system, the differing perspective images are cut into a plurality of vertical columns and interleaved to form a single, combined image. The parallax barrier strip or sheet of parallel lenticular lenses is overlaid on the combined images and functions to restrict each eye to the viewing of a different one of the interleaved images. The viewed images are then converged by the brain to give the perception of depth. This system, however, produces images with a limited viewing angle in that movement of the viewer left or right of off-center produces either a flat image or causes a reversal in the image from orthoscopic to pseudoscopic where the far and near are replaced with each other. The viewing angle limitation of a parallax barrier strip or sheet of parallel lenticular lenses becomes more pronounced when three or more differing perspective two-dimensional images are interleaved to form an autostereogram. Furthermore, true three dimensional perception of the imaged scene is not always possible, or is limited in scope as the images used to construct the combined image are usually taken from the same point of view or very few different points of view.
The foregoing systems and methods for producing stereoscopic three-dimensional photographic images have been extended to video or motion picture images. For example, the outputs of two spaced apart television cameras or motion picture cameras viewing the same scene have been directed to or projected on a display for stereoscopic viewing using binocular, alternating display, filtering or parallax apparatus. Although equally as successful as their photographic counterparts in producing three-dimensional effects, these systems also suffer equally from the same drawbacks as experienced with three-dimensional photographic images, including the limitation concerning the provision of only a single, or very limited number of points of view.
Accordingly, there is a need for an imaging and display system and method for generating true three-dimensional images.